Marinas generally provide docks extending over a body of water to provide walkways for access to boats tied to the docks. A dock can be an expansive system extending in multiple directions to accommodate various boats.
The typical dock utilizes pile glides to move up and down pilings relative to a water surface in response to tidal or wave action. As the dock moves up and down, the dock exhibits a substantially constant vertical distance from its walkway surface to the water surface. This vertical distance is known as freeboard.
Depending on dock size and a load-bearing capacity of the dock, the freeboard of the dock will be from six to thirty-six inches above the water surface. The freeboard should remain constant relative to the water surface, but over time the conventional dock can deteriorate and begin to sink; i.e., lose freeboard.
Due to the extensive, interlinked structure of some dock systems, repairing or replacing all or sections of the dock is no trivial matter. For instance, a ten-foot by four-foot by four-foot section of a concrete dock system may weigh up to ten thousand pounds. In addition to the physical challenge of removing and replacing such a section, the scrap section ultimately adds to landfill waste, which can take years to decompose.
Another drawback with the conventional dock becomes evident when an additional structure is added to the dock. If the additional structure is sufficiently heavy, the structure can exceed the load-bearing capacity of the dock in a vicinity of the added structure, which causes the dock to twist and create an uneven walkway in the vicinity of the added structure. In other words, the freeboard in that vicinity is overcome by the added weight. Thus, the load-bearing capacity of the portion of the dock bearing the additional structure must be increased to recoup the freeboard and level that portion with a remainder of the dock.
One attempt to correct degraded freeboard or to increase load-bearing capacity has included strapping a floatable device under the dock and extending the straps over the top surface of the dock. However, the straps typically connect to the floatable device with metal clamps, bolts and the like to hold the floatable device under the dock. Such metallic devices are subject to degradation in salt or brackish water, which eventually rust and allow the floatable device to break away. Moreover, the straps extending over the top surface of the dock pose a tripping hazard.
Another attempt to solve loss of dock freeboard includes placing an inflatable device under the dock and inflating the device; however, the inflatable device is typically not secured to the dock and any strong current or propeller wash (“prop wash”) can blow the inflatable device from under the dock.
Another remedy to regain freeboard includes attaching new wooden structures to the outer edges of the dock but these usually have bolts projecting from the wooden surfaces outwards and upwards of six to eight inches. The projections not only pose a safety hazard but again are subject to degradation due to salt and brackish water.
A system is needed in the marina industry to restore degraded dock freeboard and/or to provide an increased load-bearing capacity for the dock to accommodate additional structures.